EP0838924A1 - Méthode de détermination d'une valeur programmée de débit à utiliser dans un algorithme de surveillance et dispositif de surveillance correspondant - Google Patents

Méthode de détermination d'une valeur programmée de débit à utiliser dans un algorithme de surveillance et dispositif de surveillance correspondant Download PDF

Info

Publication number
EP0838924A1
EP0838924A1 EP96402253A EP96402253A EP0838924A1 EP 0838924 A1 EP0838924 A1 EP 0838924A1 EP 96402253 A EP96402253 A EP 96402253A EP 96402253 A EP96402253 A EP 96402253A EP 0838924 A1 EP0838924 A1 EP 0838924A1
Authority
EP
European Patent Office
Prior art keywords
rate
cell
policing
resource management
scheduled
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP96402253A
Other languages
German (de)
English (en)
Inventor
Johan Hilda Witters
Edouard Metz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alcatel Lucent SAS
Original Assignee
Alcatel SA
Alcatel Alsthom Compagnie Generale dElectricite
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alcatel SA, Alcatel Alsthom Compagnie Generale dElectricite filed Critical Alcatel SA
Priority to EP96402253A priority Critical patent/EP0838924A1/fr
Priority to CA002216016A priority patent/CA2216016A1/fr
Priority to US08/956,894 priority patent/US6072989A/en
Priority to JP29138597A priority patent/JPH10190696A/ja
Publication of EP0838924A1 publication Critical patent/EP0838924A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L12/5602—Bandwidth control in ATM Networks, e.g. leaky bucket
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
    • H04Q11/0428—Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
    • H04Q11/0478—Provisions for broadband connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L2012/5629—Admission control
    • H04L2012/5631—Resource management and allocation
    • H04L2012/5636—Monitoring or policing, e.g. compliance with allocated rate, corrective actions
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L2012/5638—Services, e.g. multimedia, GOS, QOS
    • H04L2012/5646—Cell characteristics, e.g. loss, delay, jitter, sequence integrity
    • H04L2012/5652—Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly

Definitions

  • the present invention relates to a method to determine a scheduled rate value as described in the preamble of claim 1, to a policing algorithm wherein the method to determine a scheduled rate value is used as defined in the preamble of claim 5, and to a policing device executing the policing algorithm as defined in the preamble of claim 9.
  • Such a method to determine a scheduled rate value such a policing algorithm and such a policing device are already known in the art, e.g. from the Contribution to the ITU Standard I.371 with reference number D.1104. This contribution is entitled 'Proposed Text on Conformance Definition for the ABR Service' and is filed in the name of United States of America .
  • a sample algorithm for policing ABR (Available Bit Rate) connections is described.
  • the origin node i.e. a source or virtual source node, regularly sends so called resource management (RM) cells in between the ATM (Asynchronous Transfer Mode) cells that contain data.
  • RM resource management
  • RM cells are interpreted by and their contents may be modified by network nodes, virtual destination nodes and/or destination nodes. Each resource management cell becomes reflected by a network or destination node to be returned to the origin node whereby it was sent.
  • FRM forward resource management cells
  • BRM backward resource management cells
  • a traffic contract specifies negotiated parameters such as the peak cell rate (PCR), the minimum cell rate (MCR), ..., and probably the conformance definition which the network provider and the subscriber mutually have to support on the connections covered by this contract.
  • a policing device in the network determines whether or not the traffic descriptors of the traffic contract are met and thereto applies the DGCRA (Dynamic Generic Cell Rate Algorithm) suggested by the ATM Forum that works on ABR standardisation.
  • the policing device thereto schedules rate values and associated time values. From the scheduled rate and time values, the policing device can determine the maximum acceptable cell transmit rate of an origin node at each instant, called the actual policing rate in the remainder of this document.
  • the above mentioned Contribution to the ITU Standard contains, from page 3 (last two lines) to page 4, line 8 , a software implementation of an algorithm that determines a scheduled rate value r(j). To determine this scheduled rate value r(j), rate control information CI(j), NI(j) ER(j) of a backward resource management cell with index j is used.
  • rate control information CI(j), NI(j) ER(j) of a backward resource management cell with index j is used.
  • source behaviour rule 5 defined on page 52 of the above cited ATM Forum Traffic Management Specification , the cell transmit rate of a source or virtual source has to be forced to the initial cell rate ICR specified in the traffic contract whenever this source or virtual source sends a new resource management cell while a certain time period has elapsed since the last forward resource management cell was sent by this source.
  • rule 6 on page 52 specifies that the cell transmit rate of a source or virtual source has to be decreased in proportion to a predetermined rate decrease factor RDF if at least a certain number, CRM, forward resource management cells are received by the policing device since the last backward resource management cell was sent from the policing device to this source or virtual source.
  • RDF rate decrease factor
  • an origin node can return at a high transmission rate after a period wherein its cell transmit rate is forced to decrease in accordance to rule 5 or rule 6. This is so because the scheduled rate r(j) is calculated solely on the basis of the contents of backward resource management cells. It is apparent to persons skilled in the art of network traffic management that this may lead to congestion somewhere in the network.
  • the known algorithm suffers some minor disadvantages.
  • the policing method disclosed in the earlier mentioned Contribution to the ITU Standard for instance does not check whether the congestion indication (CI) bit, a bit which indicates that the source transmit rate in an ABR connection has to be decreased, is set in backward resource management cells.
  • the known policing method does not realise the tightest policing conditions for ABR connections.
  • the known method also does not test cell sequence integrity.
  • Rule 3 on page 51 of the already cited ATM Forum Traffic Management Specification specifies the minimum number of ATM data cells that has to be sent between two successive forward RM cells, and the conditions that have to be fulfilled for transmission of a backward RM cell from the policing device towards the source or virtual source.
  • forward resource management cells may be flooding the network or may be sent insufficiently frequent. It is however to be noticed (see point 3 in the paragraph 5.10.6 entitled Switch behaviour ' on page 54 of the ATM Forum Specification) that cell sequence integrity may be violated for data cells if the network contains a switching node between the origin node and policing device. Yet another shortcoming of the known algorithm is that it does not check out-of-rate cell conformance. Cells marked as out-of-rate cells are subjected to rule 11 on page 52 of the already cited Specification . When the policing device does not check conformance of such cells, these out-of-rate cells may be flooding the network and cause congestion.
  • An object of the present invention is to provide a method to determine a scheduled rate value, a policing algorithm and a policing device of the above known type but which realise tighter conformance conditions and which consequently guarantee a better protection of network resources.
  • this object is achieved by the method to determine a scheduled rate value defined in claim 1, by the policing algorithm defined in claim 5, and by the policing device defined in claim 9.
  • the policing device decides to decrease the scheduled rate value proportional to the predetermined rate decrease factor RDF if already a certain number of forward resource management cells were received since the last backward RM cell arrived at the policing device. Furthermore, the scheduled rate value is forced to the initial cell rate if a certain time period has elapsed between the receipt of two forward resource management cells at the policing device. The actual policing rate used to check conformance of incoming cells is calculated from the scheduled rate values. Hence, this actual policing rate follows the above decreases and a source will no longer be allowed to return at an unacceptably high cell transmit rate after its rate was forced down.
  • An additional feature of the present method to determine a scheduled rate value is defined by claim 2.
  • a new rate value is scheduled each time a backward resource management cell arrives at the policing device.
  • information deduced at arrival of the last forward resource management cell has to be considered. This may be realised for instance via the schedule rate parameter whose value is updated at arrival of a forward RM cell and used to determine the scheduled rate value at arrival of a backward RM cell.
  • a further feature of the method to determine a scheduled rate value according to the present invention is defined in claim 3.
  • network resources are protected whenever the source transmit rate, according to rule 6 of the ABR specification, is stepwise forced to decrease. This is done when the number of backward resource management cells is substantially low compared to the number of forward resource management cells received by the policing device. This may occur for instance if a network failure prevents resource management cells to return.
  • the already mentioned ATM Forum Specification allows sources or virtual sources to transmit forward resource management cells which do not conform to the actual policing rate. Such cells have to be marked as out-of-rate cells via one of the bits, the so called CLP (Cell Loss Priority)-bit, and are allowed to be sent only at rates below TCR, the tagged cell rate. More particularly, rule 11 of the source behaviour on page 52 of the Specification is to be considered.
  • the present policing algorithm includes a step to check the conformance of these out-of-rate cells so that the network will not get flooded by out-of-rate cells.
  • a further feature of the present policing algorithm is defined in claim 7.
  • the policing device also checks rules 3a), b) and c) of the cited Specification.
  • ABR Advanced Bit Rate
  • CBR Continuous Bit Rate
  • VBR Very Bit Rate
  • the ABR service is ideal for reliable transmission of bursty data, for instance LAN (Local Area Network) data.
  • the ABR traffic contract made up between the subscriber and the network provider specifies a peak cell rate PCR that might not be exceeded by the subscriber, a minimum cell rate MCR that is always guaranteed by the provider, and some other parameters not immediately relevant with respect to the present invention, for example a maximum cell error ratio.
  • Fig. 1 shows an ATM cell switching network which supports the ABR service.
  • This ATM network includes a source S, a first virtual destination/virtual source node VD1/VS1, a policer POL, a switching node SN, a second virtual destination/virtual source node VD2/VS2, and a destination node D.
  • the source S Via the first virtual destination/virtual source node VD1/VS1 and the policer POL, the source S is coupled to the switching node SN.
  • the policer POL is located at the network interface, not drawn in Fig. 1.
  • the switching node SN is coupled to the destination node D via the second virtual destination/virtual source node VD2/VS2.
  • Source node S transmits ATM cells to destination node D regularly intercepted by forward resource management cells FRM.
  • the contents of these forward resource management cells FRM may be modified by the nodes along the path to the destination node D, i.e. by the first virtual destination/virtual source node VD1/VS1, by the switching node SN, by the second virtual destination/virtual source node VD2/VS2 or by the destination node D itself.
  • These nodes are also capable of reflecting the resource management cells FRM. Once reflected, a forward resource management cell FRM becomes a backward resource management cell BRM which travels back to the source S to allow the source S to control its cell transmit rate.
  • a resource management cell FRM or BRM, contains bit information (a Congestion Indication bit CI and a No Increase bit NI), and explicit rate information ER.
  • the source S has to decrease its transmit rate if the Congestion Indication bit CI in a backward resource management cell BRM is set, is no longer allowed to increase its transmit rate if the No Increase bit NI is set, and can increase its transmit rate if both the Congestion Indication bit CI and No Increase bit NI are not set.
  • the source S further is not allowed to exceed the explicit rate value ER in backward resource management cells BRM with its transmit rate.
  • the policer POL checks for each incoming cell whether this cell conforms to the traffic specifications in the contract. Non-conforming cells are discarded.
  • the flow charts in Fig. 2 to Fig. 7 are built up with different shaped boxes interconnected via horizontal as well as vertical lines. Via the lines a unique tree of successive steps is obtained. The branches of this tree are walked through from top to bottom and from left side to right side of the chart. The actions which have to be executed successively are represented by rectangle boxes. If the left and right side of such a rectangle box are drawn double, this box represents a procedure or cluster of actions. The actions included in this cluster are all connected to the bottom of the rectangle box with double left and right sides, and sometimes are drawn in separate figures to avoid overloading the charts. Each diamond shaped box indicates that one of two actions has to be executed.
  • a predetermined condition is fulfilled, the action or branch of actions connected to the diamond side marked by Y ' is executed. If this predetermined condition is not fulfilled, the action or branch of actions connected to the N ' marked side of the diamond box is executed.
  • the predetermined condition itself is described within the diamond shaped box. An empty box indicates that no action has to be taken.
  • Fig. 2 gives an overview of the policing algorithm.
  • Cells are treated differently depending on the direction wherein they are moving and depending on the status of their CLP bit.
  • This CLP bit is set only for out-of-rate cells: cells which do not conform to the actual policing rate APR, or more precisely: cells which do not conform to the first three rules of the source behaviour specified in the ATM Forum Specification.
  • the policer first checks whether an incoming cell is a forward moving cell, i.e. a cell which travels in the direction from the source S to the destination D, or a backward moving cell, i.e. a cell which travels in the direction from the destination D to the source S.
  • the source S and destination D may change roles depending on the connection between them that is considered.
  • S plays the role of source and D of destination node.
  • Backward moving cells are reflected forward resource management cells, in-rate or out-of-rate, and have to be analysed by the policer POL since they contain the information to control the source ' s cell transmit rate. From the contents of the backward resource management cells BRM, the policer POL calculates a scheduled rate value in the procedure New Entry for List ' .
  • This value will be used to determine the actual policing rate APR a scheduled time after the backward resource management cell BRM has been sent from the policer POL to the source S.
  • the scheduled time as well as the associated scheduled rate value are memorised by the policer POL in a scheduled rate list. If a forward moving cell arrives at the policer POL, the policer POL has to decide whether the cell conforms to the traffic descriptors of the traffic contract and the source behaviour rules defined in the earlier cited Specification.
  • the policer POL determines the actual policing rate APR from the values stored in the scheduled rate list via the procedure Determine APR ' , checks whether the cell is in accordance with the cell sequence rules 3a, 3b and 3c of the above mentioned Specification in the procedure Sequence Integrity ' , and decides that the cell conforms to the actual policing rate APR or not in the procedure entitled In-rate Conformancy ' . If the cell is mariced as an out-of-rate cell (CLP-bit is set), its conformance also has to be checked as is stated in rule 11 of the Specification.
  • Fig. 2 thereto includes the procedure Out-rate Conformancy ' . Summarising, the algorithm illustrated by Fig. 2 is executed for each cell arriving at the policer POL of Fig. 1 but the procedures that are executed depend on the nature of the arriving cell.
  • the policer POL At arrival at the policer POL of each in-rate cell, the policer POL has to consult its scheduled rate list to determine the actual policing rate APR.
  • This actual policing rate APR is to be known by the policer POL to be able to check conformance of the received in-rate cell.
  • the procedure to determine the actual policing rate APR in case the scheduled rate list includes at most two scheduled rate values and related scheduled time values, is illustrated by Fig. 3.
  • the arrival time T_cell of the cell at the policer POL is compared with the scheduled time values, T_first and T_last, in the scheduled rate list to deduce the correct actual policing rate APR.
  • the actual policing rate APR remains unchanged. If the arrival time T_cell equals or exceeds the earliest scheduled time value T_first, the actual policing rate APR becomes equal to either the first scheduled rate value R_first or last scheduled rate value R_last. If in this case the in-rate cell arrived at the policer POL at a time T_cell which exceeds the last scheduled time value T_last, the actual policing rate APR becomes the last scheduled rate value R_last. Otherwise, APR becomes equal to the first scheduled rate value R_first.
  • the list of scheduled rate values is unscheduled.
  • the Boolean parameter Scheduled ' which is given the value 0 or FALSE ' in the present software implementation.
  • the policer POL checks whether the Scheduled ' -parameter is 1 or TRUE ' each time an in-rate cell arrives before starting to determine APR. If the policer POL recognises that no rate values are scheduled, the actual policing rate APR remains unchanged.
  • the scheduled rate list is updated by replacing the oldest entry, T_first and R_first, by the more recent entry, T_last and R_last. For evident reasons, this step is executed only if the in-rate cell arrived at a time T_cell which equals or exceeds the first scheduled time value T_first. Otherwise, the scheduled rate list remains unchanged.
  • Source behaviour rule 3a on page 52 of the earlier mentioned Specification states that Nrm-1 data cells have to be sent between two successive in-rate forward resource management cells. If however a time period Trm has elapsed since transmission of the last FRM cell and at least Mrm in-rate cells have been sent by the source S, Mrm being a predetermined number smaller than Nrm, the above statement may be violated and a new forward RM cell should be sent by source S.
  • the number of data cells between two successive in-rate forward RM cells is counted via the counter Ncount. As is seen from Fig. 4, this counter Ncount is increased each time a cell is received by the policer POL except when the cell is a forward resource management cell FRM or not conform with rule 3a.
  • Ncount is reset to 0 unless the FRM cell is violating the cell sequence rules.
  • the counter Ncount is initialised to Nrm-1 at start-up of the connection between the source S and destination D since the first transmitted cell of a source S, to be in accordance with rule 2 of the ABR Specification, has to be an FRM cell. If, in view of rule 3a, the arriving cell is not conforming, cell sequence integrity is violated and the cell becomes discarded by the policer POL.
  • rule 6 of the ABR source behaviour specification states that the cell transmit rate of the source S has to decrease when at least CRM in-rate forward RM cells have been sent between receipt of two successive backward RM cells. Thereto, a counter Ccount is increased by 1 in Fig. 4 each time an in-rate forward RM cell arrives. The value of this counter Ccount will be checked for in other procedures.
  • Each in-rate cell further has to be checked to be conform with the traffic descriptors of the contract and the remaining rules of the ABR source behaviour.
  • Fig. 5A, Fig. 5B and Fig. 5C constitute the procedure to be executed. If the time permitted between sending forward resource management cells, ADTF, is exceeded, taking into account the cell delay variation tolerance CDVT, the rate is forced to the initial cell rate ICR. This is realised by modifying the time value T ICR to be equal to the arrival time Ta of the forward RM cell if the time between receipt of this forward RM cell and receipt of the last forward RM cell, Ta - Tf_last, exceeds the allowed time period ADTF + CDVT.
  • the time of arrival Ta of the cell at the policer POL is memorised as the arrival time Tf_last of the last forward RM cell for each forward RM cell arriving. From the time T ICR on, the policer POL is allowed to force the source S to the initial cell rate ICR. To be sure that it is permitted to enforce the initial cell rate ICR, the policer POL checks whether the source S received the information which allowed the source S to reduce its transmit rate in time. If the last backward RM cell passed the policer POL at a time Tb_last at least ⁇ 2 earlier then T ICR , the source S received the information in time and was able to reduce its cell transmit rate at T ICR to the initial cell rate ICR.
  • the actual policing rate APR is reduced to the minimum one of the initial cell rate ICR and the former value of APR, provided that this minimum stays between the minimum cell rate MCR and peak cell rate PCR negotiated in the traffic contract.
  • the parameter R_real and the entries in the scheduled rate list, R_first and R_last, are updated. If the last backward RM cell passed the policer POL later, APR is left unmodified because it is possible then that the source S does not decrease its rate to ICR in time.
  • Ccount the counter parameter for forward RM cells between two successive backward RM cells is initialised to 0 if the arrival time of the last backward RM cell exceeds the arrival time of the last cell Ta_last minus ⁇ 3 or the arrival time of the currently arriving cell Ta minus ⁇ 2.
  • Ccount is the counter equivalent to the counter which counts the number of transmiffed FRM cells between two received BRM cells in the source S.
  • APR may not become a value outside the range defined by the negotiated minimum cell rate MCR and peak cell rate PCR, so this has to be checked after APR is decreased. If the actual policing rate APR is changed in value, the parameter R_real and the scheduled rate values, R_first and R_last, are also updated.
  • the increase I which determines the theoretical arrival time of a cell is the minimum of a former increase value Iold and the inverse of the actual policing rate APR. If the cell arrived at a time Ta which is greater than or equal to the arrival time of the previous in-rate cell LVST, increased with the increment I, the cell conforms. It is noticed that the tolerance CDVT has to be taken into account when checking the just mentioned condition.
  • the arrival time of the previous in-rate cell, LVST is updated and becomes the maximum of the expected arrival time of a new cell, i.e.
  • LVST+I and the arrival time Ta which may be below LVST+I because of the tolerance CDVT that has to be taken into account, or which may be above LVST+I if the source does not transmit at its maximum allowable rate. Doing so, it is avoided that a source S which temporarily transmits below its allowed maximum rate, later on transmits at a rate above the maximum allowed rate. Capacity given to a source S cannot be saved up by this source S.
  • the procedure In-rate conformancy ' is terminated when the arrival time Ta is memorised as the arrival time of the last in-rate cell, Ta_last.
  • Fig. 6A and Fig. 6B illustrate the successive steps that have to be executed thereto.
  • the cell transmit rate of the source S has to be reduced by at least a term proportional to the cell transmit rate if the Congestion Indication bit CI of the received backward RM cell is set.
  • rate schedule parameter R_real is decreased with an amount R_real.RDF in this situation.
  • RDF represents the rate decrease factor which determines the proportionality between the decrease step and the cell transmit rate.
  • the rate schedule parameter R_real will be used to determine the scheduled rate values, R_first and/or R_last.
  • the reduction of the value of R_real will lead to an equivalent reduction of the scheduled rate value so that rule 8 has to be satisfied by the source S when the Congestion Indication bit CI is set, unless cells may be discarded by the policer POL.
  • the Congestion Indication bit is not set and also the No Increase bit NI is not set, the cell transmit rate of the source S is allowed to increase with a term proportional to the peak cell rate PCR. The proportionality is defined by the rate increase factor RIF. As is seen from Fig.
  • the rate schedule parameter R_real in case none of the Congestion Indication bit CI or No Increase bit NI is set, is increased with an amount PCR.RIF.
  • the scheduled rate value, R_first and/or R_last similarly to the above situation, will increase in an equivalent way. If only the No Increase bit NI is set, the actual policing rate APR does not have to be changed. Since the source S is not allowed to increase its cell transmit rate in this case, R_real is left unmodified.
  • the backward RM cell not only contains bit information but also carries an explicit rate value ER which, according to rule 9 of the ABR source behaviour specifications, might not be exceeded by the cell transmit rate of the source S.
  • rule 1 forbids the source S to transmit at rates above the negotiated peak cell rate PCR of the traffic contract.
  • the policing rate at any time has to be the minimum one of the peak cell rate PCR, the received explicit rate value ER and the rate value R_real calculated from the bit information in the backward RM cell. This minimum one moreover has to be greater than the negotiated minimum cell rate MCR.
  • the scheduled rate value, R_first and/or R_last becomes equal to this minimum cell rate MCR if the latter is untrue.
  • the so calculated rate value R_real is memorised together with an associated time value in the scheduled rate list of the policer POL.
  • the time value represents the moment from which the policer POL has to use the associated rate value to determine its actual policing rate APR and obviously may depend on the distance between policer POL and source S. This distance is unimportant for a rate increase but has to be considered for rate decreases.
  • the rate value and associated time value constitute a new entry for the scheduled rate list. How this entry is inserted in the scheduled rate list will be explained immediately by referring to Fig. 6B.
  • the policer POL as follows from Fig. 6A, also memorises the arrival time Tb of the just received and interpreted backward RM cell and indicates via its parameter Scheduled ' that a new entry became scheduled.
  • Fig. 6B illustrates the procedure to insert a new entry in the list of scheduled rate values. If the scheduled rate parameter R_real is greater than or equal to the current first scheduled rate R_first, this rate R_first is unscheduled by initialising T_last to 0 and updating the scheduled rates, R_first and R_last so that they become equal to the higher rate R_real. Additionally, the associated time T_first for the new higher rate is scheduled. T_first becomes equal to the arrival time Tb of the backward RM cell at the policer POL extended with ⁇ 3. If however the arrival time Tb of the backward RM cell is below the first scheduled time T_first, T_first is left unmodified. T_first becomes equal to the extended arrival time Tb+ ⁇ 3 if this extended arrival time Tb+ ⁇ 3 is smaller than T_first and if the calculated rate value R_real is equal to or greater than the actual policing rate APR.
  • the arrival time Tb of the backward RM cell is memorised as the arrival time Tb_last of the last backward RM cell, and the boolean parameter Scheduled ' is given the value TRUE or 1.
  • Out-of-rate cells have to be sent conform with rule 11 of the ABR source behaviour specification. Such out-of-rate cells do not have to be sent at a rate below the actual policing rate APR but have to respect a maximum out-of-rate cell rate, TCR, named the tagged cell rate. According to the ABR Standard Specification, TCR is a fixed constant of 10 cells per second. The procedure to check out-of-rate conformance, illustrated by Fig. 7 is thus less complex than the In-rate conformancy ' procedure. Only resource management cells RM are accepted as out-of-rate cells.
  • step loutrate e.g. equal to 0.1 second. In this way, it is avoided that out-of-rate cells are sent at a rate higher than TCR if, during a certain time, no out-of-rate cells were sent. In other words, a source S cannot save up out-of-rate capacity by not transmitting out-of-rate cells during a period of time.
  • the step loutrate obviously is initialised to the inverse of TCR.
  • the list of scheduled rate values in the above described embodiment is limited to two entries, application of the present invention is not limited thereto.
  • ABR Advanced Bit Rate
  • the ATM Forum proposes 2 policing algorithms, known as the DGCRA A and the DGCRA B algorithms.
  • the A algorithm differs from the B algorithm in that its list of scheduled rate values is not limited to a predetermined number of entries.
  • Algorithm B manages a list containing at most 2 scheduled rate values.
  • the use of information deduced at arrival of a forward resource management cell at the policer to determine a scheduled rate value is independent from the fact that the list contains 1, 2 or more entries.
  • RM cells may be sent out of sequence with respect to the data cells, whilst sequence integrity within the RM cell stream is maintained.
  • ABR Advanced Bit Rate

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)
EP96402253A 1996-10-23 1996-10-23 Méthode de détermination d'une valeur programmée de débit à utiliser dans un algorithme de surveillance et dispositif de surveillance correspondant Withdrawn EP0838924A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP96402253A EP0838924A1 (fr) 1996-10-23 1996-10-23 Méthode de détermination d'une valeur programmée de débit à utiliser dans un algorithme de surveillance et dispositif de surveillance correspondant
CA002216016A CA2216016A1 (fr) 1996-10-23 1997-10-07 Methode permettant de determiner une valeur de vitesse programmee a utiliser dans un algorithme, et dispositif de surveillance associe
US08/956,894 US6072989A (en) 1996-10-23 1997-10-23 Method to determine a scheduled rate value to be used in a policing algorithm, and related policing device
JP29138597A JPH10190696A (ja) 1996-10-23 1997-10-23 ポリシングアルゴリズムで使用すべき予定レート値の決定方法、及び関連するポリシング装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP96402253A EP0838924A1 (fr) 1996-10-23 1996-10-23 Méthode de détermination d'une valeur programmée de débit à utiliser dans un algorithme de surveillance et dispositif de surveillance correspondant

Publications (1)

Publication Number Publication Date
EP0838924A1 true EP0838924A1 (fr) 1998-04-29

Family

ID=8225305

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96402253A Withdrawn EP0838924A1 (fr) 1996-10-23 1996-10-23 Méthode de détermination d'une valeur programmée de débit à utiliser dans un algorithme de surveillance et dispositif de surveillance correspondant

Country Status (4)

Country Link
US (1) US6072989A (fr)
EP (1) EP0838924A1 (fr)
JP (1) JPH10190696A (fr)
CA (1) CA2216016A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7237034B2 (en) 2000-09-18 2007-06-26 Openwave Systems Inc. Method and apparatus for controlling network traffic
CN107657808A (zh) * 2017-11-17 2018-02-02 广西小草信息产业有限责任公司 一种交通管理终端和管理方法

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2240596A1 (fr) * 1997-11-28 1999-05-28 Newbridge Networks Corporation Controle des caracteristiques de transfert de couche atm base sur l'adaptation de taux dynamique de couche physique
FR2779302B1 (fr) * 1998-05-28 2000-06-23 Alsthom Cge Alcatel Controle de congestion dans un noeud atm
JP3159962B2 (ja) 1998-11-27 2001-04-23 沖電気工業株式会社 Ａｔｍ交換装置
US6331970B1 (en) * 1998-12-28 2001-12-18 Nortel Networks Limited Dynamic generic cell rate algorithm for policing ABR traffic
US6704280B1 (en) 1999-06-10 2004-03-09 Nortel Networks Limited Switching device and method for traffic policing over a network
US6466541B1 (en) * 2000-05-31 2002-10-15 Fujitsu Network Communications, Inc. Cell pacing on a network link employing a rate-based flow control protocol with underlying credit-based flow control mechanisms
US6901052B2 (en) * 2001-05-04 2005-05-31 Slt Logic Llc System and method for policing multiple data flows and multi-protocol data flows
US6944168B2 (en) * 2001-05-04 2005-09-13 Slt Logic Llc System and method for providing transformation of multi-protocol packets in a data stream
US6904057B2 (en) * 2001-05-04 2005-06-07 Slt Logic Llc Method and apparatus for providing multi-protocol, multi-stage, real-time frame classification
US7042848B2 (en) * 2001-05-04 2006-05-09 Slt Logic Llc System and method for hierarchical policing of flows and subflows of a data stream
US7161904B2 (en) * 2002-06-04 2007-01-09 Fortinet, Inc. System and method for hierarchical metering in a virtual router based network switch
US7965717B2 (en) * 2003-01-17 2011-06-21 Nortel Networks Limited Multi-staged services policing
US7779155B2 (en) * 2004-01-12 2010-08-17 Alcatel Method and systems for resource bundling in a communications network
JP4722944B2 (ja) * 2005-01-07 2011-07-13 トムソン ルーターズ グローバル リソーシーズ データベースの分散ロードのためのシステム、方法およびソフトウェア
US9438652B2 (en) 2013-04-15 2016-09-06 Opentv, Inc. Tiered content streaming

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0487235A2 (fr) * 1990-11-21 1992-05-27 AT&T Corp. Gestion de la bande passante et de la congestion pour l'accès à des réseaux à intégration de services à large bande
EP0647081A2 (fr) * 1993-09-06 1995-04-05 Kabushiki Kaisha Toshiba Méthode et appareil pour le contrôle de congestion dans un réseau de communication

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5377327A (en) * 1988-04-22 1994-12-27 Digital Equipment Corporation Congestion avoidance scheme for computer networks
US5784358A (en) * 1994-03-09 1998-07-21 Oxford Brookes University Broadband switching network with automatic bandwidth allocation in response to data cell detection
JP3568617B2 (ja) * 1995-03-24 2004-09-22 株式会社東芝 Ａｔｍ通信網におけるセル転送速度規制方法
US5546377A (en) * 1995-10-31 1996-08-13 Digital Equipment Corporation Efficient distributed method for computing max-min fair rates of a limited resource in ATM networks

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0487235A2 (fr) * 1990-11-21 1992-05-27 AT&T Corp. Gestion de la bande passante et de la congestion pour l'accès à des réseaux à intégration de services à large bande
EP0647081A2 (fr) * 1993-09-06 1995-04-05 Kabushiki Kaisha Toshiba Méthode et appareil pour le contrôle de congestion dans un réseau de communication

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
ADAMS J L ET AL: "THE SUPPORT OF THE AVAILABLE BIT RATE BEARER CAPABILITY USING VIRTUAL SOURCE/DESTINATION CONCEPTS", BT TECHNOLOGY JOURNAL, vol. 13, no. 3, 1 July 1995 (1995-07-01), pages 67 - 79, XP000543499 *
ATM FORUM TRAFFIC MANAGEMENT SPECIFICATION VERSION 4., February 1996 (1996-02-01), pages 51 - 52
BONOMI F ET AL: "THE RATE-BASED FLOW CONTROL FRAMEWORK FOR THE AVAILABLE BIT RATE ATM SERVICE", IEEE NETWORK: THE MAGAZINE OF COMPUTER COMMUNICATIONS, vol. 9, no. 2, 1 March 1995 (1995-03-01), pages 25 - 39, XP000493487 *
RICKARD N.: "ABR: Realizing the Promise of ATM.", TELECOMMUNICATIONS., vol. 29, no. 4, April 1995 (1995-04-01)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7237034B2 (en) 2000-09-18 2007-06-26 Openwave Systems Inc. Method and apparatus for controlling network traffic
CN107657808A (zh) * 2017-11-17 2018-02-02 广西小草信息产业有限责任公司 一种交通管理终端和管理方法

Also Published As

Publication number Publication date
JPH10190696A (ja) 1998-07-21
CA2216016A1 (fr) 1998-04-23
US6072989A (en) 2000-06-06

Similar Documents

Publication Publication Date Title
US6072989A (en) Method to determine a scheduled rate value to be used in a policing algorithm, and related policing device
Chao et al. Quality of service control in high-speed networks
EP0499150B1 (fr) Procédé et système pour contrÔler de débit des paquets dans un réseau de communication
US5936940A (en) Adaptive rate-based congestion control in packet networks
EP0879520B1 (fr) Maitrise des flux et des encombrements dans des reseaux a commutation de paquets
US6005843A (en) Virtual source/virtual destination device of asynchronous transfer mode network
Niestegge The ‘leaky bucket’policing method in the atm (asynchronous transfer mode) network
EP0647081B1 (fr) Méthode et appareil pour le contrôle de congestion dans un réseau de communication
EP0784895B1 (fr) Procede et dispositif de regulation de flux destines a des reseaux de communication a base de cellules
Rasmussen et al. Source-independent call acceptance procedures in ATM networks
US6385168B1 (en) Fair share bandwidth allocation algorithm and device
CA2164489A1 (fr) Gestion du trafic et controle de l'encombrement dans les reseaux de transmission de paquets
EP0800294B1 (fr) Méthode de contrôle de débit de données, noeud de réseau à file d'attente et réseau de commutation de paquets
US6587436B1 (en) Method and apparatus for allocation of available bandwidth
US6560195B1 (en) Method and apparatus for leaky bucket based out-bound shaping in an ATM scheduler
Wallmeier A connection acceptance algorithm for ATM networks based on mean and peak bit rates
Davies et al. End-to-end management of mixed applications across networks
Marzo i Lázaro Enhanced Convolution Approach for CAC in ATM Networks, an analytical study and implementation
KR0175486B1 (ko) 비동기전달모드 간격제어기의 재방출간격 제어방법
JP3203610B2 (ja) セル流制御装置
Chatterjee et al. Dynamic congestion control schemes in high-speed multimedia networks
Liebeherr et al. A multi-level explicit rate control scheme for ABR traffic with heterogeneous service requirements
Jong et al. Algorithms on dynamic priority scheduling for heterogeneous traffic in ATM
Lee et al. Simple measurement-based connection admission control for heterogeneous traffic sources
KR0129609B1 (ko) 사용변수제어/망변수제어의(upc/npc) 적응적 셀간격 조정방법

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE ES FI FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19981029

AKX Designation fees paid

Free format text: AT BE CH DE ES FI FR GB IT LI NL SE

RBV Designated contracting states (corrected)

Designated state(s): AT BE CH DE ES FI FR GB IT LI NL SE

RAP3 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ALCATEL

RAP3 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ALCATEL

17Q First examination report despatched

Effective date: 20010301

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20040410